Exploring potential induction of grapevine (Vitis spp.) root phenolic compounds by ring nematodes, Mesocriconema...

Ring nematodes can decrease vineyard productivity when plated in conditions favorable for their survival. Resistant rootstocks are available to combat harm due to ring nematodes, and compounds called phenolics were hypothesized as imparting this resistance. Therefore, this study measured phenolic compound levels in four different rootstocks and attempted to find associations with ring nematode populations. Furthermore, select phenolics called stilbenoids were tested in a bioassay to observe if these compounds affect ring nematode survival. This was part of a larger effort to assess the role of phenolics in protecting grapevines from nematodes and other pathogens or pests.

This study was conducted over 2 years, 2018 and 2019, and phenolic levels were much greater in 2019 than 2018 likely due to uncontrolled differences in climatic controls. Ring nematode infected grapevines also did not have different phenolic compound levels than healthy controls. Bioassays of different stilbenoid polymers revealed no significant effects on ring nematode survival. These results suggest that analyzed root phenolic compounds were not involved in resistance or susceptibility to ring nematodes. These data should steer future researchers into analyzing other potential sources of nematode resistance.